Do you have a reference to show that changing lenses without turning camera off can hurt the camera or lens? This matter is so trivial that I am not going to look for it. Besides, then you will claim that somebody is full of it too. But I read about it years ago on one of the forums most likely on DPReview and that is why I mentioned it. Think about it. Opening the card door shuts off many cameras, would you think releasing the lens would not disconnect something? If this matter was so important it would be posted everywhere and it would be bigger than left point focusing problem, oil spots in D600 or light leak from top LCD on Canon 5D3. Yet there is nothing out there about this unimportant matter.